1. Field of the Invention
The present invention relates to a glass base material drawing apparatus which draws a glass rod. More particularly the glass base material drawing apparatus is capable of drawing a glass rod until the outside diameter of the glass rod reaches a prescribed value to obtain a glass rod having a prescribed diameter (for example, an optical fiber base material).
2. Description of the Related Art
FIG. 1 is a schematic drawing of the neighborhood of a heating furnace of a glass base material drawing apparatus nearby according to the prior art When an optical fiber base material is drawn until the diameter of the optical fiber base material reaches a desired value, it is necessary to prevent foreign materials in the air from adhering to the pre-drawn glass base material 11 before the pre-drawn glass base material 11 is placed in a heating furnace 13. In order to achieve this objective, the glass base material 11 must be held in a storing container 12 before the glass base material 11 is placed in the heating furnace 13. In the prior art, a cylindrical container as shown in FIG. 3 was used as a storing container, and the cylindrical container was kept airtight by closing the top of the storing container 12 with a lid 16.
When the conventional cylindrical container 12 is used, however, the glass base material 11 needs to be shifted temporarily upward above the storing container 12 in order to install the glass base material 11 to the drawing apparatus. For this reason, the glass base material drawing apparatus is made very large. As the size of the glass base material 11 is increased, the size of the storing container is also increased. As a result, the size of the drawing apparatus is also increased. Therefore, the operation efficiency of the drawing apparatus deteriorates.
Given this problem, it is an object of the present invention to provide a method for drawing a glass base material and a glass base material drawing apparatus which solve the above-state problem.
According to the first aspect of the present invention, a glass base material drawing apparatus for heating and drawing a glass base material is provided. This glass base material drawing apparatus has a storage unit for storing the glass base material having an opening unit that is opened along the longitudinal direction of the storage unit when the glass base material is placed inside the storage unit, a heating unit for heating the glass base material that has been stored inside the storage unit via the opening unit, and a pull-out unit for pulling out the glass base material heated by the heating unit.
The opening unit may be opened in such a manner that the glass base material is moved from a side direction of the storage unit into the interior of the storage unit. A main axis for supporting the glass base material is connected to the glass base material. The storage unit may have a penetration hole through which the main axis is inserted when the opening unit is closed.
The opening unit may be opened in such a manner that the main axis is installable from a side direction of the storage unit to a position that passes through the penetration hole. When the opening unit is opened, at least a portion of the circumference of the penetration hole may be opened. The storage unit may have, for example, a cylindrical pipe unit and an end surface formed on the top surface of the pipe unit. The opening unit may be formed at the center of the end surface.
The storage unit is divisible into two or more sub-storage units along the axial direction of the storage unit. The opening unit may be opened by moving at least one of the sub-storage units away from the remaining sub-storage units. The storage unit may further have hinges which couple the two or more sub-storage units with each other. The storage unit may be divisible into two sub-storage units by a plane that passes through the axis of the storage unit.